CN204089203U - Based on the new type mining reactive-load compensator of modularization three-level structure - Google Patents

Abstract

The utility model provides a kind of new type mining reactive-load compensator based on modularization three-level structure, comprise interconnective main loop unit and control unit, main loop unit comprises the input reactance device, phase shifting transformer and the three level power conversion unit that connect successively, and control unit comprises control signal collecting unit, control algolithm realizes unit, control signal issue unit.The utility model can produce capacitive reactive power neatly, also can produce perception idle, capacitive reactive power to perceptual idle, otherwise or, can fast tunable continuously.

Description

New mining reactive power compensator based on modular three-level structure

technical field

The utility model relates to a compensator, in particular to a novel reactive power compensator for mines based on a modularized three-level structure.

Background technique

The main electrical loads in the coal mine power grid are asynchronous motor loads, and these inductive loads consume a large amount of reactive power. In order to avoid the voltage shock of starting these asynchronous motors, some motors adopt variable frequency starting or transmission mode, but the harmonic suppression and reactive power compensation of the system are still the main considerations of the mine power grid. The reactive power impact will cause the grid voltage to fluctuate, and the harmonics will cause the deterioration of the grid power supply quality. Harmonics cause heating or burning of electromechanical equipment such as motors, which will cause insulation degradation and aging of power supply lines and electrical equipment, and easily cause leakage, short circuit and other faults. Therefore, it is especially important to use effective methods for harmonic suppression and reactive power comprehensive treatment to mine safety production and system energy saving, and to improve equipment operation reliability.

The traditional static var compensator (Static Var Compensator, SVC) refers to the static var power generating device or reactive power absorbing device connected in parallel whose output changes with the specific control parameters of the power system. It mainly relies on power electronic devices such as thyristors to complete the adjustment or switching of energy storage elements (capacitors or reactances). This mode is essentially the way to change reactance, this SVC mode is variable reactance mode. For example, the TCR mode can only change the inductive reactive power of the system, and cannot realize continuous adjustment from capacitive reactive power to inductive reactive power. Due to the use of thyristor devices, there is a situation that it can only be turned on and cannot be turned off, and the SVC in this mode also generates a certain amount of harmonics.

Utility model content

In view of the defects in the prior art, the purpose of this utility model is to provide a new type of reactive power compensator for mines based on a modular three-level structure, which can flexibly generate capacitive reactive power and inductive reactive power, Capacitive reactive power to inductive reactive power, or vice versa, can be adjusted continuously and quickly. It is a new type of reactive power compensator for mines, which has important application significance for mine special power grids.

According to one aspect of the utility model, a new type of reactive power compensator for mining based on a modular three-level structure is provided, which is characterized in that it includes a main circuit unit and a control unit connected to each other, and the main circuit unit includes sequentially connected input A reactor, a phase-shifting transformer and a three-level power conversion unit, the control unit includes a control signal acquisition unit, a control algorithm realization unit, and a control signal sending unit.

Preferably, the three-level power conversion unit is composed of insulated gate bipolar transistors.

Preferably, the three-level power conversion unit is composed of an insulated gate bipolar transistor and a capacitor.

Preferably, the control signal acquisition unit is composed of a voltage sensor and a current sensor connected to each other.

Preferably, the voltage sensor is an AV100-2000 voltage sensor produced by LEM; the current sensor is an LT508-S6 current sensor produced by LEM.

Preferably, the control algorithm implementation unit is a digital signal processor.

Preferably, the digital signal processor adopts a TMS320F28335 chip produced by Texas Instruments.

Preferably, the control signal sending unit is a field programmable gate array chip.

Preferably, the field programmable gate array chip is a ProASIC3A3P250 chip produced by Actel.

Compared with the prior art, the utility model has the following beneficial effects: the utility model can flexibly generate capacitive reactive power and inductive reactive power by controlling the amplitude and phase of the output voltage of the three-level power conversion unit, Capacitive reactive power to inductive reactive power, or vice versa, can be adjusted continuously and quickly, and can realize the function of active filtering. It is a new type of reactive power compensator for mines, which has important application significance for mine special power grids.

Description of drawings

Other features, objects and advantages of the present invention will become more apparent by reading the detailed description of non-limiting embodiments with reference to the following drawings:

Fig. 1 is a schematic structural diagram of a new mining reactive power compensator based on a modular three-level structure of the present invention.

Fig. 2 is a schematic diagram of the electrical structure of the phase-shifting transformer in the utility model.

Fig. 3 is a schematic diagram of the electrical structure of the three-level power conversion unit in the present invention.

Fig. 4 is a schematic diagram of the capacitive reactive experimental waveform issued by the utility model.

Fig. 5 is a schematic diagram of the experimental waveform of inductive reactive power emitted by the utility model.

Fig. 6 is a schematic diagram of the utility model switching from sending capacitive reactive power to sending inductive reactive power dynamic experimental waveform.

Detailed ways

The utility model is described in detail below in conjunction with specific embodiments. The following examples will help those skilled in the art to further understand the utility model, but do not limit the utility model in any form. It should be noted that those skilled in the art can make several modifications and improvements without departing from the concept of the present utility model. These all belong to the protection domain of the present utility model.

As shown in Figure 1, the utility model based on the modular three-level structure of the new mining reactive power compensator includes a main circuit unit 1 and a control unit 2 connected to each other, and adopts a reactive power detection method based on the instantaneous reactive power theory. Taking the grid-side power factor as the control target, it dynamically tracks the change of the power quality of the grid, and adjusts the reactive power output according to the change, so as to realize the high-quality operation of the grid; the main circuit unit 1 includes an input reactor 3 and a phase-shifting transformer 4 connected in sequence and a three-level power conversion unit 5; the control unit 2 includes a control signal acquisition unit 6, a control algorithm implementation unit 7, and a control signal sending unit 8. The control unit 2 realizes the full digital control of the reactive power compensator through the digital signal processor (DSP) and the field programmable gate array (FPGA) chip, adopts voltage and current digital closed-loop and PWM (Pulse-WidthModulation) modulation technology, and the control signal adopts Optical fiber transmission realizes high and low voltage isolation and improves the stability and reliability of the reactive power compensator. The digital signal processor (DSP) adopts the TMS320F28335 chip produced by Texas Instruments; the field programmable gate array (FPGA) chip adopts the ProASIC3A3P250 chip produced by Aite Company.

The input reactor 3 suppresses the sudden change of current caused by grid instability and the influence of instability on the reactive power compensator, protects the reactive power compensator, prolongs its service life and prevents harmonic interference, and can improve the power of the reactive power compensator at the same time Factor and restrain harmonic current, filter out harmonic voltage and harmonic current, and improve power grid quality.

The input reactor adopts the SVL-0350-EISC-2680 three-phase reactor produced by Shanghai Yingfeng Electronic Technology Co., Ltd., and its rated inductance is 0.6mH.

As shown in FIG. 2 , the phase-shifting transformer 4 is a dry-type transformer, which adopts a multiple design to reduce input harmonics. The primary winding of the transformer is connected to the input reactor, and there are two secondary windings on the secondary winding, which are respectively connected by Δ/Δ (Dd0) and Δ/Y (Dy11) to shift the phase of the output voltage of the secondary side by 30 degrees. The level power conversion units are respectively powered by a group of secondary sides of the transformer, and the three-level power conversion units 5 and the secondary sides of the transformer are insulated from each other. The phase-shifting transformer 4 makes each three-level power conversion unit 5 independent of each other through electrical isolation to realize voltage superposition and series connection. At the same time, the phase-shifting connection method can effectively eliminate harmonics below the eleventh order, and the input current waveform is close to a sine wave. The total harmonic current distortion rate can be lower than 5%.

As shown in Figure 3, the three-level power conversion unit 5 is composed of an insulated gate bipolar transistor (IGBT) and a capacitor and is connected to the phase-shifting transformer 4. Its topology is simple, its performance is reliable, and it is assisted by a small-capacity energy storage element , The output line voltage of the reactive power compensator is composed of five levels, which improves the withstand voltage value of the system and makes the system structure easy to expand. Compared with the traditional two-level structure, it has higher system capacity and smaller output waveform harmonic content, which can avoid the large du/dt caused by the traditional two-level structure as the voltage level increases. various problems.

The control signal acquisition unit 6 is composed of voltage sensors and current sensors connected to each other. The voltage sensor is used to detect the grid voltage and the capacitor side voltage in real time; the current sensor is used to detect the load current and the output current of the reactive power compensator in real time. The grid voltage and load current are used to calculate the reactive power of the grid, the capacitor side voltage is used to realize the DC side capacitor midpoint potential balance control, and the output current of the reactive power compensator is used for the closed-loop control of the reactive power compensator control system.

The control algorithm implementation unit 7 is a digital signal processor (DSP). The control algorithm of the reactive power compensator is realized in the digital signal processor (DSP), and the sensor signal is input into the digital signal processor (DSP) through A/D conversion for operation control. The control algorithm unit completes functions such as top-level algorithm, system protection, sub-module control and protection, etc. The control algorithm unit calculates the given value of the reactive power compensator after receiving the grid voltage, current and the capacitor voltage and current signals of each bottom unit, and then sends the control signal to the control signal sending unit.

The control signal sending unit 8 is a field programmable gate array (FPGA) chip. The field programmable gate array (FPGA) chip obtains the modulation signal of the PWM waveform from the digital signal processor (DSP), and then compares it with the triangular wave to generate the PWM waveform, and then controls the switching device of the three-level power unit through the driving module. Field Programmable Gate Array (FPGA) chip mainly completes pulse distribution, data exchange with digital signal processor (DSP) and system protection.

The insulated gate bipolar transistor (IGBT) adopts the FF650R17IE4 module produced by Infineon. The voltage sensor adopts the AV100-2000 voltage sensor produced by LEM Company; the current sensor adopts the LT508-S6 current sensor produced by LEM Company. The digital signal processor (DSP) adopts a TMS320F28335 chip produced by Texas Instruments. The field programmable gate array (FPGA) chip adopts the ProASIC3A3P250 chip produced by Aite Company.

Fig. 4 shows that the utility model sends out the capacitive reactive power experiment waveform, the terminal line voltage waveform 9 of the mine reactive power compensator outputs a five-level waveform, the output current waveform 11 of the mine reactive power compensator is similar to a sine wave, and is ahead of the grid line voltage The waveform is 10 and 60 degrees, and capacitive reactive power is emitted.

Fig. 5 shows that the utility model sends out the inductive reactive test waveform, the mine reactive power compensator terminal line voltage waveform 9 outputs a five-level waveform, the mine reactive power compensator output current waveform 11 is similar to a sine wave, and lags behind the grid line voltage waveform 10 one hundred and twenty degrees, send out inductive reactive power.

Fig. 6 shows that the utility model switches from sending capacitive reactive power to sending inductive reactive dynamic experimental waveform, and the reactive current reference value is stepped from 150A (sending capacitive reactive power) to -150A (sending inductive reactive power), The step response of the output current waveform of the reactive power compensator for mining is very fast, and the response time is shorter than 10ms.

The utility model based on the modularized three-level structure of the new mining reactive power compensator can flexibly generate capacitive reactive power, and can also generate inductive reactive power, from capacitive reactive power to inductive reactive power, or vice versa, can be continuously and rapidly It is a new type of reactive power compensator for mines, and it can realize the function of active filtering. It has important application significance for mine special power grids.

The specific embodiments of the present utility model have been described above. It should be understood that the utility model is not limited to the above-mentioned specific embodiments, and those skilled in the art can make various changes or modifications within the scope of the claims, which does not affect the essence of the utility model.

Claims (8)

1. A novel mining reactive power compensator based on a modularized three-level structure is characterized in that it comprises an interconnected main circuit unit and a control unit, and the main circuit unit comprises an input reactor, a phase-shifting transformer and The three-level power conversion unit, the control unit includes a control signal acquisition unit, a control algorithm realization unit, and a control signal sending unit. 2. The novel mine-used reactive power compensator based on a modular three-level structure according to claim 1, wherein the three-level power conversion unit is composed of an insulated gate bipolar transistor and a capacitor. 3. The novel mine reactive power compensator based on the modularized three-level structure according to claim 1, wherein the control signal acquisition unit is composed of a voltage sensor and a current sensor connected to each other. 4. The novel mine reactive power compensator based on modular three-level structure according to claim 3, characterized in that, the voltage sensor adopts the AV100-2000 voltage sensor produced by LEM Company; the current sensor adopts LEM The LT508-S6 current sensor produced by the company. 5. The novel reactive power compensator for mines based on a modular three-level structure according to claim 1, wherein the control algorithm implementation unit is a digital signal processor. 6. The novel mine reactive power compensator based on the modularized three-level structure according to claim 5, wherein the digital signal processor adopts a TMS320F28335 chip produced by Texas Instruments. 7. The novel mining reactive power compensator based on a modular three-level structure according to claim 1, wherein the control signal sending unit is a field programmable gate array chip. 8. The novel mining reactive power compensator based on the modularized three-level structure according to claim 7, wherein the field programmable gate array chip adopts the ProASIC3A3P250 chip produced by Aite Company.